Field of the Invention
The invention relates generally to processing of audio performances and, in particular, to computational techniques suitable for generating a pitch track from vocal audio performances sourced from a plurality of performers and captured at a respective plurality of vocal capture platforms.
Description of the Related Art
The installed base of mobile phones, personal media players, and portable computing devices, together with media streamers and television set-top boxes, grows in sheer number and computational power each day. Hyper-ubiquitous and deeply entrenched in the lifestyles of people around the world, many of these devices transcend cultural and economic barriers. Computationally, these computing devices offer speed and storage capabilities comparable to engineering workstation or workgroup computers from less than ten years ago, and typically include powerful media processors, rendering them suitable for real-time sound synthesis and other musical applications. Partly as a result, some modern devices, such as iPhone®, iPad®, iPod Touch® and other iOS® or Android devices, support audio and video processing quite capably, while at the same time providing platforms suitable for advanced user interfaces. Indeed, applications such as the Smule Ocarina™, Leaf Trombone®, I Am T-Pain™, AutoRap®, Sing! Karaoke™, Guitar! By Smule®, and Magic Piano® apps available from Smule, Inc. have shown that advanced digital acoustic techniques may be delivered using such devices in ways that provide compelling musical experiences.
One application domain in which exploitations of digital acoustic techniques have proven particularly successful is audiovisual performance capture, including karaoke-style capture of vocal audio. For vocal capture applications designed to appeal to a mass-market and for at least some user demographics, an important contributor to user experience can be the availability of a large catalog of high-quality vocal scores, including vocal pitch tracks for the very latest musical performances popularized by a currently popular set of vocal artists. Because the set of currently popular vocalists and performances is constantly changing, it can be a daunting task to generate and maintain a content library that includes vocal pitch tracks for an ever changing set of titles.
As a result, many karaoke-style applications omit features that might otherwise be desirable if suitable content, including vocal pitch tracks, were readily available for new music releases and works for which vocal scores are not widely published. In contrast, some features of advanced karaoke-style vocal capture implementations and, indeed, some compelling aspects of the user experience thereof, including provision of performance-synchronized (or synchronizable) vocal pitch cues, real-time continuous pitch correction of captured vocal performances, auto-harmony generation, user performance grading, competitions etc., can depend upon availability of high-quality musical scores, including pitch tracks.
To support these and other features, automated and/or semi-automated techniques are desired for production of musical scoring content, including pitch tracks. In particular, automated and/or semi-automated techniques are desired for production of vocal pitch tracks for use in mass-market, karaoke-style vocal capture applications.